Ok guys... take the time to listen what i have done and solved the problem.

I removed everything from my case... and start installing the parts one after the other... when i installed the 2nd ram stick the pc started the reboot cycle again.
I removed the one stick.... and i was working with the other.. everyting worked out fine....
I installed windows xp again everything from the begining.
I bouth 2 kingston 512 ram sticks and i installed them.
Till today everything works fine......

I used to have a similar problem with XP, but it was more to do with my mouse software
zErO i had a usb microsoft mouse.. and yesterday when i opened the case to install the ram when i booted my pc the optical mouse had a problem and it wasnt working properly. I got a usb to ps2 adapter and now everything works fine now.
It might be the same problem but i for sure the one ram stick had a problem.

Thanks guys for your support and suggestions